| 摘要 |
PURPOSE:To effect the drive in accordance with a load applied thereby to reduce the electric power by feeding drive pulses to a step motor, while having their width stepwise elongated or shortened, so that the operation may be started with the drive pulses of the minimum width after the stopped condition is released. CONSTITUTION:The drive pulses of a step motor are composed of two kinds of normal drive pulses P1 and auxiliary drive pulses P2. If the step motor cannot be turned by the normal pulses P1, the auxiliary pulses P2 are supplied. With the supply of the auxiliary pulses P2, the pulse width of the subsequent normal pulses is so elongated to facilitate the rotations. When, on the contrary, the rotations can be accomplished several steps, the width of the subsequent pulses is shortened. Thus, the supply of the drive pulses can be effected stepwise. When the time metering is restarted after the stop, the normal drive pulses have their width set at the minimum one of the pulse width prepared, and thereafter the stepwise supply is accomplished. |
